[Buildroot] [PATCHv3] package/gcc/9.3.0: fix host-gcc-final when ccache is used

[Yann E. MORIN <yann.morin.1998@free.fr>]

Romain, All,

On 2020-05-21 18:53 +0200, Romain Naour spake thusly:
> As reported by several Buildroot users [1][2][3], the gcc build
> may fail while running selftests makefile target.
> 
> The problem only occurs when ccache is used with gcc 9 and 10,
> probably due to a race condition.
> 
> While debuging with "make -p" we can notice that s-selftest-c target
> contain only "cc1" as dependency instead of cc1 and SELFTEST_DEPS [4].
> 
>   s-selftest-c: cc1
> 
> While the build is failing, the s-selftest-c dependencies recipe is
> still running and reported as a bug by make.
> 
>   "Dependencies recipe running (THIS IS A BUG)."
> 
> A change [5] in gcc 9 seems to introduce the problem since we can't
> reproduce this problem with gcc 8.
> 
> As suggested by Yann E. MORIN [6], move SELFTEST_DEPS before
> including language makefile fragments.
> 
> With the fix applied, the s-seltest-c dependency contains
> SELFTEST_DEPS value.
> 
>   s-selftest-c: cc1 xgcc specs stmp-int-hdrs ../../gcc/testsuite/selftests
> 
> [1] http://lists.busybox.net/pipermail/buildroot/2020-May/282171.html
> [2] http://lists.busybox.net/pipermail/buildroot/2020-May/282766.html
> [3] https://github.com/cirosantilli/linux-kernel-module-cheat/issues/108
> [4] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/c/Make-lang.in;h=bfae6fd2549c4f728816cd355fa9739dcc08fcde;hb=033eb5671769a4c681a44aad08a454e667e08502#l120
> [5] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=033eb5671769a4c681a44aad08a454e667e08502
> [6] http://lists.busybox.net/pipermail/buildroot/2020-May/283213.html
> 
> Signed-off-by: Romain Naour <romain.naour@gmail.com>
> Cc: Ben Dakin-Norris <ben.dakin-norris@navtechradar.com>
> Cc: Maxim Kochetkov <fido_max@inbox.ru>
> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> Cc: Yann E. MORIN <yann.morin.1998@free.fr>

Applied to master, thanks.

Regards,
Yann E. MORIN.

> ---
>  ...move-SELFTEST_DEPS-before-including-.patch | 81 +++++++++++++++++++
>  1 file changed, 81 insertions(+)
>  create mode 100644 package/gcc/9.3.0/0004-gcc-Makefile.in-move-SELFTEST_DEPS-before-including-.patch
> 
> diff --git a/package/gcc/9.3.0/0004-gcc-Makefile.in-move-SELFTEST_DEPS-before-including-.patch b/package/gcc/9.3.0/0004-gcc-Makefile.in-move-SELFTEST_DEPS-before-including-.patch
> new file mode 100644
> index 0000000000..227d35a7f0
> --- /dev/null
> +++ b/package/gcc/9.3.0/0004-gcc-Makefile.in-move-SELFTEST_DEPS-before-including-.patch
> @@ -0,0 +1,81 @@
> +From 811c8d628045c3d248144fc560a4bf80209ca16e Mon Sep 17 00:00:00 2001
> +From: Romain Naour <romain.naour@gmail.com>
> +Date: Thu, 21 May 2020 15:58:02 +0200
> +Subject: [PATCH] gcc/Makefile.in: move SELFTEST_DEPS before including language
> + makefile fragments
> +
> +As reported by several Buildroot users [1][2][3], the gcc build
> +may fail while running selftests makefile target.
> +
> +The problem only occurs when ccache is used with gcc 9 and 10,
> +probably due to a race condition.
> +
> +While debuging with "make -p" we can notice that s-selftest-c target
> +contain only "cc1" as dependency instead of cc1 and SELFTEST_DEPS [4].
> +
> +  s-selftest-c: cc1
> +
> +While the build is failing, the s-selftest-c dependencies recipe is
> +still running and reported as a bug by make.
> +
> +  "Dependencies recipe running (THIS IS A BUG)."
> +
> +A change [5] in gcc 9 seems to introduce the problem since we can't
> +reproduce this problem with gcc 8.
> +
> +As suggested by Yann E. MORIN [6], move SELFTEST_DEPS before
> +including language makefile fragments.
> +
> +With the fix applied, the s-seltest-c dependency contains
> +SELFTEST_DEPS value.
> +
> +  s-selftest-c: cc1 xgcc specs stmp-int-hdrs ../../gcc/testsuite/selftests
> +
> +[1] http://lists.busybox.net/pipermail/buildroot/2020-May/282171.html
> +[2] http://lists.busybox.net/pipermail/buildroot/2020-May/282766.html
> +[3] https://github.com/cirosantilli/linux-kernel-module-cheat/issues/108
> +[4] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/c/Make-lang.in;h=bfae6fd2549c4f728816cd355fa9739dcc08fcde;hb=033eb5671769a4c681a44aad08a454e667e08502#l120
> +[5] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=033eb5671769a4c681a44aad08a454e667e08502
> +[6] http://lists.busybox.net/pipermail/buildroot/2020-May/283213.html
> +
> +Upstream status: https://gcc.gnu.org/pipermail/gcc-patches/2020-May/546248.html
> +
> +Signed-off-by: Romain Naour <romain.naour@gmail.com>
> +Cc: Ben Dakin-Norris <ben.dakin-norris@navtechradar.com>
> +Cc: Maxim Kochetkov <fido_max@inbox.ru>
> +Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> +Cc: Yann E. MORIN <yann.morin.1998@free.fr>
> +Cc: Cc: David Malcolm <dmalcolm@gcc.gnu.org>
> +---
> +This patch should be backported to gcc 10 and gcc 9.
> +---
> + gcc/Makefile.in | 6 ++++--
> + 1 file changed, 4 insertions(+), 2 deletions(-)
> +
> +diff --git a/gcc/Makefile.in b/gcc/Makefile.in
> +index abae872cd63..e2ef3c46afc 100644
> +--- a/gcc/Makefile.in
> ++++ b/gcc/Makefile.in
> +@@ -1686,6 +1686,10 @@ $(FULL_DRIVER_NAME): ./xgcc
> + 	rm -f $@
> + 	$(LN_S) $< $@
> + 
> ++# SELFTEST_DEPS need to be set before including language makefile fragments.
> ++# Otherwise $(SELFTEST_DEPS) is empty when used from various <LANG>/Make-lang.in.
> ++SELFTEST_DEPS = $(GCC_PASSES) stmp-int-hdrs $(srcdir)/testsuite/selftests
> ++
> + #

> + # Language makefile fragments.
> + 
> +@@ -1950,8 +1954,6 @@ DEVNULL=$(if $(findstring mingw,$(build)),nul,/dev/null)
> + SELFTEST_FLAGS = -nostdinc $(DEVNULL) -S -o $(DEVNULL) \
> + 	-fself-test=$(srcdir)/testsuite/selftests
> + 
> +-SELFTEST_DEPS = $(GCC_PASSES) stmp-int-hdrs $(srcdir)/testsuite/selftests
> +-
> + # Run the selftests during the build once we have a driver and the frontend,
> + # so that self-test failures are caught as early as possible.
> + # Use "s-selftest-FE" to ensure that we only run the selftests if the
> +-- 
> +2.25.4
> +
> -- 
> 2.25.4
> 

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